This invention relates to a half-tone image reproducing method, and more particularly to such a method in which a half-tone image contained in a colored or monochromatic image is reproducible.
There are known various types of methods for forming an image, such as a thermal transfer type, a laser printing type. All of these methods are usually performed in the mode of a binary recording. In order to reproduce a half-tone image, it is necessary to employ a dither method. If the dither method is employed under the binary recording mode, each pixel has 10 gradations including white if it is composed of 3 dots .times.3 dots, or 17 gradations also including white if it is composed of 4 dots .times.4 dots. Neither the resolution or gradation can be improved without the sacrifice of the other.
There is also known a color image recording method using a photosensitive pressure-sensitive recording sheet as a recording medium. In forming an image thereon, mask originals are used, each carrying a light shielding image corresponding to each of three primary colors on a light transmissive base plate. In this method, the recording sheet is superposedly exposed to lights through the respective mask originals to superposedly form a latent image thereon and is then pressure developed to form a visible image on the same sheet or a separate sheet. According to this method, however, the mask originals are produced by a monochromatic binary output device, such as a thermal transfer printer or a laser printer, so that if the mask originals are produced by the dither method to reproduce half-tone images, the same problelm as that mentioned above is involved.